How do you find the percentage for NaCi

Where are the following questions

A1 a 2 a 3 ooh lol i think that's it

Hello thereone of the following properties was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version. which property fits this description? answer: atomic mass  was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.